Re: [cf-satellite] Coordinate variables - center vs. corner of the pixel

• To: cf-satellite@xxxxxxxxxxxxxxxx
• Subject: Re: [cf-satellite] Coordinate variables - center vs. corner of the pixel
• From: Martin Raspaud <martin.raspaud@xxxxxxx>
• Date: Thu, 16 Dec 2010 07:37:39 +0100

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2010-12-14 19:33, Gail L Schmidt skrev:
> 
> I'm wondering if there is a standard for center vs. corner when writing
> the coordinate variables for latitude/longitude or projection x/y of
> satellite imagery for netCDF?  GeoTIFF supports both conventions.  HDF
> appears to specify the UL corner of the pixel.  Has anyone settled on a
> convention for netCDF or CF Metadata in general?

Hi Gail,

In the conventions, I read this:
"""
The values of a coordinate variable or auxiliary coordinate variable indicate
the locations of the gridpoints. The locations of the boundaries between cells
are indicated by bounds variables (see Section 7.1, “Cell Boundaries”). If
bounds are not provided, an application might reasonably assume the gridpoints
to be at the centers of the cells, but we do not require that in this standard.
"""
(introduction of chapter 4: Coordinate Types)

I would consider them as the center then.

Best regards,
Martin
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• References:
  • [cf-satellite] Coordinate variables - center vs. corner of the pixel
    • From: Gail L Schmidt